Effectiveness of cyclohexyl functionality in ugonins from Helminthostachys zeylanica to PTP1B and α-glucosidase inhibitions

From waste to wonder: exploring the hypoglycemic and anti-oxidant properties of corn processing by-products

Introduction: The industrial processing of corn (Zeamays L.) generates by-products such as corn silk, straw peels, and straw core, which contribute to adverse environmental impacts. Our study aimed to investigate sustainable approaches for mitigating these effects by evaluating the hypoglycemic potential and mechanisms of ethyl acetate fractions derived from these corn derivatives. Methods: We employed glucose consumption assays, high glucose stress tests, UPLC-QE-Orbitrap-MS analysis, molecular docking, and simulations to assess their components and efficacy. Antioxidant capacities were evaluated using DPPH, FRAP, ABTS, and •OH scavenging assays. Results: Notably, the ethyl acetate fraction extracted from straw peels (SPE) exhibited a high concentration of flavonoids and phenolic compounds along with pronounced hypoglycemic activity and antioxidant capacity. SPE significantly enhanced glucose consumption in insulin-resistant HepG2 cells while protecting HUVECs against damage caused by high glucose levels. Molecular docking analyses confirmed the interaction between active compounds and α-glucosidase as well as α-amylase, while molecular dynamic simulations indicated stability at their binding sites. Discussion: In conclusion, the hypoglycemic and antioxidative properties observed in corn by-products such as straw peels, corn silk, and straw core can be attributed to the inhibition of α-glucosidase and α-amylase activities, coupled with their rich phenolic and flavonoid content. These findings highlight the potential of these by-products for applications in healthcare management and their sustainable utilization, demonstrating significant value in the use of agricultural residues.

Unveiling Anti-Diabetic Potential of Baicalin and Baicalein from Baikal Skullcap: LC-MS, In Silico, and In Vitro Studies

Type 2 diabetes mellitus (T2DM) is marked by persistent hyperglycemia, insulin resistance, and pancreatic β-cell dysfunction, imposing substantial health burdens and elevating the risk of systemic complications and cardiovascular diseases. While the pathogenesis of diabetes remains elusive, a cyclical relationship between insulin resistance and inflammation is acknowledged, wherein inflammation exacerbates insulin resistance, perpetuating a deleterious cycle. Consequently, anti-inflammatory interventions offer a therapeutic avenue for T2DM management. In this study, a herb called Baikal skullcap, renowned for its repertoire of bioactive compounds with anti-inflammatory potential, is posited as a promising source for novel T2DM therapeutic strategies. Our study probed the anti-diabetic properties of compounds from Baikal skullcap via network pharmacology, molecular docking, and cellular assays, concentrating on their dual modulatory effects on diabetes through Protein Tyrosine Phosphatase 1B (PTP1B) enzyme inhibition and anti-inflammatory actions. We identified the major compounds in Baikal skullcap using liquid chromatography-mass spectrometry (LC-MS), highlighting six flavonoids, including the well-studied baicalein, as potent inhibitors of PTP1B. Furthermore, cellular experiments revealed that baicalin and baicalein exhibited enhanced anti-inflammatory responses compared to the active constituents of licorice, a known anti-inflammatory agent in TCM. Our findings confirmed that baicalin and baicalein mitigate diabetes via two distinct pathways: PTP1B inhibition and anti-inflammatory effects. Additionally, we have identified six flavonoid molecules with substantial potential for drug development, thereby augmenting the T2DM pharmacotherapeutic arsenal and promoting the integration of herb-derived treatments into modern pharmacology.

Analogues of Dihydroflavonol and Flavone as Protein Tyrosine Phosphatase 1B Inhibitors from the Leaves of Artocarpus elasticus

Protein tyrosine phosphatase 1B (PTP1B) is one of the target enzymes whose disruption leads to obesity and diabetes. A series of PTP1B inhibitors were isolated from the leaves of Artocarpus elasticus, used in traditional medicines for diabetes. The isolated inhibitors (1-13), including two new compounds (1 and 2), consisted of dihydroflavonols and flavones. The structural requirements for the PTP1B inhibitory mode and potency were revealed in both skeletons. The two highest PTP1B inhibitory properties were dihydroflavonol 1 and flavone 6 analogs with IC50 values of 0.17 and 0.79 μM, respectively. The stereochemistry also affected inhibitory potencies: trans isomer 1 (IC50= 0.17 μM) vs cis isomer 2 (IC50= 2.24 μM). Surprisingly, the dihydroflavonol and flavone glycosides (11 and 13) displayed potent inhibition with IC50s of 2.39 and 0.22 μM, respectively. Furthermore, competitive inhibitor 1 was applied to time-dependence experiments as a simple slow-binding inhibitor with parameters of Kiapp = 0.064103 μM, k3 = 0.2262 μM-1 min-1, and k4 = 0.0145 min-1. The binding affinities by using the fluorescence quenching experiment were highly correlated with inhibitory potencies: 1 (IC50= 0.17 μM, KSV = 0.4375 × 105 L·mol-1) vs 3 (IC50= 17.79 μM, KSV = 0.0006 × 105 L·mol-1). The specific binding interactions were estimated at active and allosteric sites according to the inhibitory mode by molecular docking.

Saponin and Fatty Acid Profiling of the Sea Cucumber Holothuria atra, α-Glucosidase Inhibitory Activity and the Identification of a Novel Triterpene Glycoside

Saponin-rich sea cucumber extracts have shown antidiabetic effects in a few reports. Although the triterpene glycosides of sea cucumbers are commonly isolated from their Cuvierian tubules, these are absent in Holothuria atra Jaeger. Therefore, this study intended to investigate the saponin profile in the body wall of H. atra, as well as to assess the α-glucosidase inhibitory activity of the H. atra extracts. The chemical profiling of sea cucumber extracts was conducted by UPLC-HRMS analysis. This resulted in the tentative identification of 11 compounds, 7 of which have not been reported in the H. Atra body wall before. Additionally, two triterpene glycosides were purified and their structures were elucidated based on HRMS and NMR data: desholothurin B (1), and a novel epimer, 12-epi-desholothurin B (2). Moreover, the fatty acid profile of the H. atra body wall was investigated by GC-MS. It was found that the Me90 fraction of the H. atra body wall showed the strongest α-glucosidase inhibitory activity (IC₅₀ value 0.158 ± 0.002 mg/mL), thus making it more potent than acarbose (IC₅₀ value 2.340 ± 0.044 mg/mL).

Antioxidant, Tyrosinase, α-Glucosidase, and Elastase Enzyme Inhibition Activities of Optimized Unripe Ajwa Date Pulp (Phoenix dactylifera) Extracts by Response Surface Methodology

The Ajwa date (Phoenix dactylifera L., Arecaceae family) is a popular edible fruit consumed all over the world. The profiling of the polyphenolic compounds of optimized unripe Ajwa date pulp (URADP) extracts is scarce. The aim of this study was to extract polyphenols from URADP as effectively as possible by using response surface methodology (RSM). A central composite design (CCD) was used to optimize the extraction conditions with respect to ethanol concentration, extraction time, and temperature and to achieve the maximum amount of polyphenolic compounds. High-resolution mass spectrometry was used to identify the URADP's polyphenolic compounds. The DPPH-, ABTS-radical scavenging, α-glucosidase, elastase and tyrosinase enzyme inhibition of optimized extracts of URADP was also evaluated. According to RSM, the highest amounts of TPC (24.25 ± 1.02 mgGAE/g) and TFC (23.98 ± 0.65 mgCAE/g) were obtained at 52% ethanol, 81 min time, and 63 °C. Seventy (70) secondary metabolites, including phenolic, flavonoids, fatty acids, and sugar, were discovered using high-resolution mass spectrometry. In addition, twelve (12) new phytoconstituents were identified for the first time in this plant. Optimized URADP extract showed inhibition of DPPH-radical (IC₅₀ = 87.56 mg/mL), ABTS-radical (IC₅₀ = 172.36 mg/mL), α-glucosidase (IC₅₀ = 221.59 mg/mL), elastase (IC₅₀ = 372.25 mg/mL) and tyrosinase (IC₅₀ = 59.53 mg/mL) enzymes. The results revealed a significant amount of phytoconstituents, making it an excellent contender for the pharmaceutical and food industries.

Status of research on natural protein tyrosine phosphatase 1B inhibitors as potential antidiabetic agents: Update

Protein tyrosine phosphatase 1B (PTP1B) is a crucial therapeutic target for multiple human diseases comprising type 2 diabetes (T2DM) and obesity because it is a seminal part of a negative regulator in both insulin and leptin signaling pathways. PTP1B inhibitors increase insulin receptor sensitivity and have the ability to cure insulin resistance-related diseases. However, the few PTP1B inhibitors that entered the clinic (Ertiprotafib, ISIS-113715, Trodusquemine, and JTT-551) were discontinued due to side effects or low selectivity. Molecules with broad chemical diversity extracted from natural products have been reported to be potent PTP1B inhibitors with few side effects. This article summarizes the recent PTP1B inhibitors extracted from natural products, clarifying the current research progress, and providing new options for designing new and effective PTP1B inhibitors.

Soybean phytochemicals responsible for bacterial neuraminidase inhibition and their characterization by UPLC-ESI-TOF/MS

Ethanol extract of soybean (Glycine max (L.) Merr.) showed good inhibitory activity against bacterial neuraminidase (BNA), which plays a pivotal role in the pathogenesis of a number of microbial diseases. The saponin portion fractionated through preparative HPLC (IC50 = 2.25 μg mL-1) was found to be responsible for the observed BNA inhibition. Estimation of the inhibitory effects by individual compounds showed that the soyasaponins of group B (Ba, Bb, Bb', Bc, and Bd) exhibited extremely high inhibitions (IC50 = 0.25-0.48 μM), whereas group A (Aa, Ab, and Ac) was almost inactive. Kinetic studies determined that group B soyasaponins were noncompetitive inhibitors. Furthermore, molecular docking experiments confirmed that soyasaponin Ba (group B) could undergo binding interactions with various residues in the binding pocket. In contrast, soyasaponin Aa (group A) failed to enter the binding pocket due to its extra scaffold structure of oligosaccharides bonded to the 22-hydroxyl position. The metabolites in the soybean extract were fully characterized using UPLC-ESI-TOF/MS.

Inhibition of Bacterial Neuraminidase and Biofilm Formation by Ugonins Isolated From Helminthostachys Zeylanica (L.) Hook

Bacterial neuraminidase (BNA) plays a pivotal role in the pathogenesis of several microbial diseases including biofilm formation. The aim of this study is to reveal the neuraminidase inhibitory potential of metabolites from Helminthostachys zeylanica (L.) Hook. which have diverse biological activities including PTP1B and α-glucosidase. The six ugonins (1–6) from the target plant showed significant neuraminidase inhibition. The inhibitory potencies were observed at a nanomolar level of 35–50 nM, which means they are 100 times more active than their corresponding mother compounds (eriodyctiol and luteolin). A detailed kinetic study revealed that all ugonins were reversible noncompetitive inhibitors. An in-depth investigation of the most potent compound 1 showed its time-dependent inhibition with the isomerization model having k₅ = 0.0103 min⁻¹, k₆ = 0.0486 min⁻¹, and K_i^app = 0.062 μM. The binding affinities (K_sv) were agreed closely with our prediction based on the inhibitory potencies. Particularly, ugonin J (1) blocked the biofilm formation of E. coli dose-dependently up to 150 µM without the inhibition of bacteria. The major compounds (1–6) in the extract were characterized by UPLC-ESI-Q-TOF/MS.

Antioxidant, Anti-Inflammatory, and Antidiabetic Activities of Bioactive Compounds from the Fruits of Livistona chinensis Based on Network Pharmacology Prediction

In this study, a chemical investigation on the fruits of Livistona chinensis (FLC) led to the isolation and identification of 45 polyphenols and 5 alkaloids, including two new compounds (Livischinol (1) and Livischinine A (46)), an undescribed compound (47) and 47 known compounds. FLC was predicted with novel potential antidiabetic function by collecting and analyzing the potential targets of the ingredients. Compound 32 exhibited significant α-glucosidase inhibitory activity (IC₅₀ = 5.71 μM) and 1, 6, and 44 showed the PTP1B inhibitory activity with IC₅₀ values of 9.41-22.19 μM, while that of oleanolic acid was 28.58 μM. The competitive inhibitors of PTP1B (compounds 1 and 44) formed strong binding affinity, with catalytic active sites, proved by kinetic analysis, fluorescence spectra measurements, and computational simulations, and stimulated glucose uptake in the insulin-resistant HepG2 cells at the dose of 50 μM. In addition, FLC was rich in antioxidant and anti-inflammatory bioactive compounds so that they could be developed as nutraceuticals against diabetes.

Natural α-Glucosidase and Protein Tyrosine Phosphatase 1B Inhibitors: A Source of Scaffold Molecules for Synthesis of New Multitarget Antidiabetic Drugs

Diabetes mellitus (DM) represents a group of metabolic disorders that leads to acute and long-term serious complications and is considered a worldwide sanitary emergence. Type 2 diabetes (T2D) represents about 90% of all cases of diabetes, and even if several drugs are actually available for its treatment, in the long term, they show limited effectiveness. Most traditional drugs are designed to act on a specific biological target, but the complexity of the current pathologies has demonstrated that molecules hitting more than one target may be safer and more effective. The purpose of this review is to shed light on the natural compounds known as α-glucosidase and Protein Tyrosine Phosphatase 1B (PTP1B) dual-inhibitors that could be used as lead compounds to generate new multitarget antidiabetic drugs for treatment of T2D.